When I got mine initially, they had leaves but the leaves had alot of black spots on them, and they died off. It's been a few months now and no new leaves have come up. Do I need to break off the little bits of remaining stems where the leaves were to stimulate some new growth?
I have the rhizomes tied onto the top of a rock in a low light tank without co2 or ferts. There's plenty of bio-load from the fish. I wanted to end up with lots of java fern, but at this rate it may be decades.
The rhizomes are still green and firm... still alive. It's odd they aren't growing.
Try putting them in a jar of water on a sunny windowsill, and see if the higher light doesn't get them growing. Change the water as needed, and don't let them get too hot (if you're in a warm climate).